Some embodiments are already known of reels formed by a cylindrical central body and two end discs which can be removably coupled to the cylindrical central body.
Demountable reels are particularly interesting as once the material stored on them has been consumed, they can be disassembled and sent, in parts, to their corresponding place of origin or supplier, who will be in charge of storing the consumable used on the reel. The fact that the reels are demountable favours their reuse, since transportation or storage costs are greatly reduced in comparison to conventional non-demountable reels. The possibility of disassembling the reel permits the parts comprising it, once uncoupled, to be conveniently placed in boxes or packaging whose volume/weight ratio is much more advantageous than in the case of non-demountable reels.
The patent document EP 0342739 discloses a demountable reel comprising a cylindrical central element and end discs connected thereto, said central element being formed by two sections removably interconnected on an axial plane.
The central element is equipped at its ends with outer grooves that are removably coupled, by rotating the central tube, to coupling parts of the discs, in a position whereat the discs enclose and maintain the sections of the central element joined together. It is fitted together by the housing of protuberances or projections of the disc coupling means in the corresponding recesses of the cylindrical central element. Once coupled, the reel can be disassembled by rotating the central tubes and by elastic deformation of the coupled parts.
In other types of embodiment, the cylindrical central body is equipped at its ends with a respective annular flange which projects outwards and each disc is equipped with an annular groove on the centre of the internal face of the disc, defining a continuous annular cavity adapted to removably house the flanges of the hollow cylindrical central body.
To this effect, an example of a known reel is disclosed in the document ES 1035834 U, wherein the central tube of the reel has, at its ends, projections which fit into notches of the end discs, but in this case said projections are equipped with first elastic elements that fit into indentations, located in the notches of the end discs, when a relative rotation of the tube takes place in relation to the disc improving the coupling of the previous embodiment. Nevertheless, to detach the central tube from the end discs an opening is required on the side of the disc opposite the central tube of the reel to handle the elastic elements using an appropriate tool e.g. a screwdriver or the point of a pen. Furthermore, said embodiment requires second elastic elements, different to the first, so that once the reel is coupled it prevents it from uncoupling when the central tube rotates in the opposite direction to that performed to couple it to the discs.
Although the known embodiments permit the assembly of the reels and their subsequent disassembly, they are not free from problems. Although the discs are coupled to the ends of the main cylindrical body, they remain attached thereto provided that one tries to separate them by exerting a force axially, being able to uncouple the reel by forcing the main body to rotate in relation to the discs. Furthermore, the embodiments that aim to correct said problem, as is the case of document ES 1035834 U, require tools to be able to disassemble the reel.
Furthermore, both embodiments require elastic elements, which, with time, and after successive assembling and disassembling operations, can undergo breakages or simple wear and tear, so that the coupling of the parts is progressively weaker, and may cause the reel to disassemble when being handled or during its use in a machine.
The lack is therefore felt of a demountable reel whose coupling means cannot be worn or, at least, have the least possible, practically negligible, wear, which is in turn easy to assemble, further ensuring that its parts remain suitably coupled despite possible rotation stresses that the cylindrical central body may undergo in relation to the end discs.